Hydraulic brake system flusher and bleeder



Nov. 21, 1939. F. w. SCHAFER ET AL HYDRAULIC BRAKE SYSTEM FLUSHER AND BLEEDER 'Filed May 27, 1937 Patented Nov. 21, 1939 HYDRAULIC BRAKE SYSTEM FLUSHER AND BLEEDER Fred W. Schafer and George W. Stephens, Denver, Colo.

Application May 27, 1937, Serial No. 145.162

1 Claim.

This invention relates to an improved method and apparatus for flushing and refilling a hydraulic brake system.

The object of the invention is to provide means 5 to introduce under pressure a cleaning fluid to a brake system to flush out the old brake fluid and any foreign matter that may be contained therein.

Another object of the invention is to suecessively flush the conduits leading to the different brakes, and to employ the fresh brake fluid to exhaust the cleaning fluid remaining in the system.

A further object of the invention is to employ the same apparatus to first flush the system and to then refill the same.

Other objects and advantages of the invention will become apparent from the specification of which the drawing forms a part, and wherein- Figure l is an elevational view of the device connected to the master cylinder of a brake system, and

Figure 2 is a central vertical sectional'view of the container.

Referring more particularly to the drawing wherein like reference characters designate like or corresponding parts in the difierent views, a closed container I is provided with a side wall ll, top l2 and concave bottom l3.

A liquid level tube 14 is mounted on the L shaped pipes l5 mounted in wall II and communicating with the interior of container Ill. An inlet I6 is provided in top l2, and is adapted to be closed by a threaded plug I1. Top l2 also mounts an air intake valve IS, a blow off valve IS, an air pressure gauge 20, and a handle 2!. Bottom I3 is provided with an outlet 22 adapted to receive a threaded plug 23.

A pipe 24 provided with a downturned end 25 is mounted in plug 25 which is secured in opening 21 in wall H.

The exposed end of pipe 24 is connected to one end of a hose 28 which is provided with a shut off valve 29. The opposite end of hose 28 is secured to pipe 3|! connected to adapter 3| which is secured in the inlet 32 of the master cylinder 33. An exhaust valve 3 5 is mounted on adapter 3i.

Container i0- is intended to be first partially filled with alcohol not to exceed the level 01 the upper arrow 35. Plug l1 isthen replaced and air is introduced under pressure by means of valve I8 to a predetermined pressure to be indicated on gauge 20. If the pressure in container l0 becomes excessive it will be automatically released through blow off valve l9. Valve 29 is then opened permitting the alcohol under pressure to be forced through hose 28 into the master cylinder 33. Each of the conduits (not shown) from the master cylinder to the brake drums is provided with a bleeder valve. These bleeder valves are opened one at a time to permit the alcohol to force the old brake fluid and what foreign matter may be in the pipe out through the valve. When the alcohol runs clear the valve is closed and the next valve is opened and the operation repeated. Plug 23 is then removed and container I0 is drained. Container I0 is then partially filled with brake fluid and air under pressure is again introduced into the container l0. Valve 29 is then opened admitting the brake fluid to cylinder 33. The bleeder valves are opened to allow the brake fluid to force out any remaining alcohol. The bleeder valves are then closed and after the system is filled exhaust valve 34 is opened to release any air which may be in the system. Adapter 3| is then removed and the system is sealed and ready for use.

'It is to be understood that only the preferred embodiment of the invention has been shown, the right being reserved to make such changes and modifications as do not depart from the spirit and scope of the invention.

We claim as our invention:

In a self-contained apparatus for flushing and bleeding hydraulic brake systems, an air tight tank having inlet and outlet openings provided with plugs for filling and draining said tank, an air valve for supplying compressed air thereto. a blow-oil valve to release excess pressure, said tank having a raised concave bottom, a conduit connected adjacent one of its ends to said tank, said end depending downwardly into said bottom, an adapter connected to the opposite end of said conduit and adapted to be connected to the inlet of a brake system master cylinder, and an exhaust valve mounted in said adapter for releasing the air from said system.

FRED W. SCHAFER. GEORGE W. STEPHENS. 

